Colorized micron sized free flowing fillers

ABSTRACT

Disclosed are compositions of fillers coated with adhesion promoting material alone, or also coated with an additive, processes for producing the coated fillers, the fillers obtained from those processes, and methods of using the coated fillers. The filler particle(s) are surface-treated with a component which assists in the adhesion/adherence of an additive to the filler particles, resulting in the desired additive-coated fillers. The filler, adhesion promoting material and additive can be mixed in slurry and dried, and the resulting filler particles are directly useful in many applications, such as paper coatings, plastic compositions (both foamed and non-foamed), inks, paints, cosmetics, textiles and the like, wherever such fillers now find application. Preferably, the additive is a colorant.

CROSS-REFERENCED APPLICATIONS

This application is a continuation application of, and claims priorityto, U.S. patent application Ser. No. 15/586,916, filed May 4, 2017, nowallowed, which in turn is a divisional application of, and claimspriority to, U.S. patent application Ser. No. 14/278,148, filed May 15,2014, now U.S. Pat. No. 9,701,843, which in turn claims priority to U.S.Provisional Application No. 61/823,489, filed May 15, 2013, all of whichare incorporated herein in their entirety by reference thereto.

BACKGROUND 1. Field of the Disclosure

The present disclosure relates to compositions comprised of free flowingmicron sized colorized fillers, processes for producing the fillers,fillers obtained from those processes, and methods of using the fillers.

2. Background of the Disclosure

U.S. Pat. No. 3,950,180 relates to so-called inexpensive coloringcomposites comprising inorganic substances as main component combinedwith organic basic colored compounds.

U.S. Pat. No. 4,084,983 relates to colored lustrous pigments havingspecial color effects. This object is said to be attained by binding thedyestuff primarily chemically on the surface of the pigment particles.

U.S. Pat. No. 4,444,592 relates to blue-hued pigments which are thereaction product of water-insoluble aryl pararosaniline compounds andheteropoly acids (illustratively phosphomolybdic acid or phosphotungsticacid) and the process of their manufacture.

U.S. Pat. No. 4,543,128 relates to colored composition comprising anaqueous paste or dispersion of a filler which has been dyed with awater-soluble polycationic dyestuff.

U.S. Pat. No. 4,609,404 relates to organic dyes containing a silanegroup which are insoluble in water and suitable to provide compositepigments by grafting onto the surface of an inorganic substrate.

U.S. Pat. No. 4,655,843 relates to diimidic tetracarboxylic perylenedyes having chemically combined therewith at least one silane group, andto the corresponding silane composite pigments, prepared by associationthereof with an inorganic solid substrate.

U.S. Pat. No. 4,773,936 relates to water-insoluble pigment comprising acomplex of a water-insoluble inorganic substrate exhibiting anionexchange properties, a water-soluble dye, and an anionic amphipathicmaterial is disclosed.

U.S. Pat. No. 5,106,420 relates to water-soluble organic dyes which havebeen insolubilized or “fixed” onto various mineral pigment substrates tothereby form mineral-based coloring pigments.

U.S. Pat. No. 5,458,680 relates to the preparation of chemicallyaggregated composite pigments, using organo-silicon compounds. Theproducts are said to be useful as fillers and in coatings for paper.

U.S. Pat. No. 5,650,003 relates to a composition containing TiO₂ andcalcined clay in a weight ratio of between about 30:70 and 70:30, thatis substantially free of a functional microgel component.

U.S. Pat. No. 5,653,794 relates to a process for the production ofhydrophobic inorganic oxide products which comprises reacting theinorganic oxide particles with organohalosilanes, preferablyorganochlorosilanes, to produce hydrophobic organosilane coatedinorganic oxides.

U.S. Pat. No. 6,379,452 relates to calcined kaolin clay pigments said tohave improved color manufactured by adding a blue agent to the kaolinclay pigment prior to calcination, and then calcining the pigment andblue agent mixture.

U.S. Pat. Nos. 6,436,538 and 6,706,330 relate to a collection ofcomposite platelet-like particles comprising a core and at least onecoating layer consisting essentially of a compound having from 60 to 95%by weight of carbon and from 5 to 25% by weight of nitrogen, the balanceto 100% being selected from elements of the group consisting ofhydrogen, oxygen and sulfur.

SUMMARY OF THE DISCLOSURE

In one embodiment, the present disclosure relates to proceses forpreparing filler compositions comprising one or more fillers having asubstantially uniform coating of a material which promotesadhesion/adherence of desired additives to a plurality of the coatedfiller(s), the coated filler compositions obtained by such processes,the use of the coated filler(s) in applications which call for such afiller to be included, and the processes for obtaining the resultingproducts from the use of such coated filler(s) in the mentionedapplications. The filler particle(s) have been surface-treated with acomponent, the component assisting in the adhesion/adherence of anadditive to the filler particles, resulting in the filler-containingadditives which are an object of this disclosure. The filler, additive,and component can be mixed in aqueous slurry, dried and the resultingfiller particles are directly useful in many applications, such as papercoatings, plastic compositions (both foamed and non-foamed), inks,paints, cosmetics, textiles and the like, wherever such fillers now findapplication. The additive can be tailored to accommodate the particularneeds of the particular use contemplated.

Fillers which find application in the present disclosure include anyfiller or particulate material which is desired to be used in anyparticular application by the end user. The only requirement of thefiller itself is that it be insoluble, or substantially insoluble, inthe medium in which it is slurried. The filler can be in any shape orform, i.e., fibrillar, sphere-like, tubular, etc. Preferably used asfillers are calcium carbonate particles, zeolite particles, halloysites,PTFE particles, perlite, stabilizers, pumice, pumice perlite, whiterock, talc, wood fiber, expanded perlite, and sodium potassium aluminumsilicate, to name a few classes of such fillers. Most preferable arecalcium carbonate particles, zeolite particles, PTFE particles andhalloysites. These fillers and others are widely known. The filler(s)preferably are micron sized.

The fillers are coated with a material which promotes adhesion of adesired additive to the filler. Preferably, the adhesion-promotingmaterial is comprised of one or more thermoplastic neutralizedethylene-acrylic acid copolymers. As used herein, the phrase“substantially uniform” means that at least about 50%, preferably atleast about 60%, more preferably at least about 75%, most preferably atleast about 85-90% and especially preferably at least about 90-95% ormore of the surface area of the particle(s) sought to be coated with thematerial and/or additive are so-coated. Also, a “plurality of” as usedherein means at least about 50%, preferably at least about 60%, morepreferably at least about 75%, most preferably at least about 85-90% andespecially preferably at least about 90-95% or more of the fillersand/or other target of the coating of material or additive aresubstantially uniformly coated, as mentioned above.

In another embodiment, the present disclosure relates to furthertreating the resulting substantially uniformly coated fillercompositions as described above with an additive which imparts to thefiller desired additive properites for use in further processes andapplications. The additive which can be added to the substantiallyuniformly coated filler compositions may be selected from colorants,fire retardants, nucleating agents useful in producing foamed polymericcompositions, antioxdizing agents, and other such related additives.

Also, though in general terms coated fillers may be known in the art, ithas heretofore been difficult to obtain such fillers which are micronsized yet free flowing powders, especially when coated. Agglomeration isone of the problems faced when coating such fillers, and suchagglomeration precludes the resulting fillers from being free flowing.The free flowing characteristic of the disclosed fillers in micron sizesis obtained by the use of a specific drying method which allows for theproduction of such fillers.

In one embodiment, the present disclosure provides processes forproducing substantially uniformly coated filler compositions comprisedof the following steps:

(a) preparing a mixture or slurry of filler in a medium to form aslurried suspension or mixture of filler;

(b) adding to the slurried suspension or mixture obtained in step (a) amaterial which promotes adhesion/adherence of desired additive(s) to thefiller to form coated filler slurried suspension or mixture having asubstantially unifom coating of said adhesion/adherence promotingmaterial to a plurality of filler to obtain a coated filler;

(c) adding to the coated filler obtained in step (b) an additive whichimparts to the filler desired additive properties to form a slurriedsuspension or mixture of additive-containing filler; and

(d) drying the additive-containing filler to obtain particles comprisedof filler, adhesion-promoting material and additive. Preferably, theparticles are free-flowing and a plurality of the particles aresubstantially uniformly coated particles, substantially uniformly coatedwith the additive.

The above steps (a), (b), and (c) can be performed sequentially orconcurrently; that is, the filler may be collected and packaged and thenlater slurried to form the suspension as set forth in step (a), thencollected and later coated with the material as set forth in step (b)and again collected and later treated with the desired additive as setforth in step (c).

Alternatively, the process may be carried out by performing anycombination of steps and then the resulting filler product collected.Still further, alternatively, all of steps (a), (b), and (c) may beperformed sequentially one after the other. Specifically, the filler maybe suspended, the adhesion/adherence promoting material may be added tothat suspension to form the substantially uniformly coated filler, andthe additive may be added to that substantially uniformly coated filler,all in the same vessel, performed sequentially.

A further aspect of the present disclosure are the filler compositionsresulting from the processes set forth above. In one embodiment of suchaspect, the substantially uniformly coated filler, having a coating ofadherence/adhesion promoting material, resulting from step (b) above,may be collected and saved for later use. Still further, the fillerresulting from step (c) in the above processes may be collected andsaved for later use.

Still further, the present disclosure contemplates the use of theobtained filler compositions as additives in further processes forprocessing or treating substrates to obtain products having desiredproperties imparted or enhanced by the filler compositions of thepresent disclosure. For example, the filler compositions of the presentdisclosure may be used in further processes to impart or enhance desiredproperties such as color, fire retardance, anti-drip properties,nucleation site creation, and/or lubrication to such products as papercoatings, plastic compositions (both foamed and non-foamed), inks,paints, cosmetics, textiles, building materials and the like, whereverappropriate filler(s) now find application.

DETAILED DESCRIPTION OF THE DISCLOSURE

The disclosure will now be described in respect of the preferredfillers, the preferred adherence/adhesion promoting material, and thepreferred additive. The preferred fillers include calcium carbonate,halloysites, PTFE particles and zeolite; the preferredadherence/adhesion promoting material includes neutralizedethylene-acrylic acid (EAA) copolymers; and the preferred additive isone or more colorant(s).

Preferred Fillers

Calcium carbonate is a chemical substance, represented by the chemicalformula CaCO₃. It is estimated that about 4 percent of the Earth's crustis made up of calcium carbonate. The calcium carbonate cycle is composedof rocks, minerals, water, plants and animals. It is found naturally asminerals and rocks, some of which include calcite, limestone, chalk,marble and aragonite. Minerals and rocks impart calcium carbonate innatural water sources, resulting in hard water. In fact, calciumcarbonate is the main cause of water hardness. It is also a majorconstituent compound of the shells and skeletons of animals. Calciumcarbonate is used in many aspects of life, either in naturally occurringstate or pure form. Pure calcium carbonate is extracted from naturalsources by means of various techniques like mining and quarrying. Theconstituent elements and chemical properties of calcium carbonate makeit a favorable substance for use in therapeutic purposes and many otherindustries. The main use of calcium carbonate is in the constructionindustry, either as a building material or limestone aggregate for roadbuilding or as an ingredient of cement or as the starting material forthe preparation of builder's lime by burning in a kiln. However, due toweathering, mainly caused by acid rain, calcium carbonate (in limestoneform) is no longer used for building purposes on its own, and only as araw/primary substance for building materials.

Calcium carbonate is also used in the purification of iron from iron orein a blast furnace. Calcium carbonate is calcined in situ to givecalcium oxide, which forms a slag with various impurities present, andseparates from the purified iron. Calcium carbonate is also used in theoil industry in drilling fluid as a formation bridging and filter cakesealing agent and may also be used as a weighting material to increasethe density of drilling fluids to control down-hole pressures.Precipitated calcium carbonate, pre-dispersed in slurry form, is alsonow widely used as filler material for latex gloves with the aim ofachieving maximum saving in material and production costs. Calciumcarbonate is widely used as an extender in paints, in particular matteemulsion paints where typically 30% by weight of the paint is eitherchalk or marble. Calcium carbonate is also widely used as a filler inplastics. Some typical examples include around 15 to 20% loading ofchalk in unplasticized polyvinyl chloride drain pipe, 5 to 15% loadingof stearate coated chalk or marble in unplasticized polyvinyl chloridewindow profile. PVC cables can use calcium carbonate at loadings of upto 70 parts per hundred parts of resin to improve mechanical properties(tensile strength and elongation) and electrical properties (volumeresistivity). Polypropylene compounds are often filled with calciumcarbonate to increase rigidity, a requirement that becomes important athigh use temperatures. CaCO₃ is also routinely used as filler inthermosetting resins and has also been mixed with ABS, and otheringredients, to form some types of compression molded “clay” Pokerchips. Fine ground calcium carbonate is an essential ingredient in themicroporous film used in babies' diapers and some building films as thepores are nucleated around the calcium carbonate particles during themanufacture of the film by biaxial stretching.

Calcium carbonate is also used in a wide range of trade anddo-it-yourself adhesives, sealants, and decorating fillers. Ceramic tileadhesives typically contain 70 to 80% limestone. Decorating crackfillers contain similar levels of marble or dolomite. Calcium carbonateis also mixed with putty in setting windows, and as a resist to preventglass from sticking to kiln shelves when firing glazes and paints athigh temperature. Calcium carbonate is known as whiting inceramics/glazing applications, where it is used as a common ingredientfor many glazes in its white powdered form. When a glaze containingcalcium carbonate is fired in a kiln, the whiting acts as a fluxmaterial in the glaze.

Ground Calcium Carbonate (GCC) or Precipitated Calcium Carbonate (PCC)is used as filler in paper. GCC and PCC are cheaper than wood fiber, soadding these to paper is cost efficient for the paper industry. Printingand writing paper can be made of 10-20% calcium carbonate. In NorthAmerica, calcium carbonate has begun to replace kaolin in the productionof glossy paper. Europe has been practicing this as alkalinepapermaking, or acid-free papermaking, for some decades. Calciumcarbonates are available in various forms: ground calcium carbonate(GCC) or precipitated calcium carbonate (PCC). The latter has a veryfine and controlled particle size, on the order of 2 micrometers indiameter, useful in coatings for paper. It is commonly called chalk asit has traditionally been a major component of blackboard chalk. Modernmanufactured chalk is now mostly gypsum, hydrated calcium sulfateCaSO₄.2H₂O. Ground calcium carbonate is further used as an abrasive(both as scouring powder and as an ingredient of household scouringcreams), in particular in its calcite form, which has the substantiallylow hardness level of 3 on the Mohs scale of mineral hardness, and willtherefore not scratch glass and most other ceramics, enamel, bronze,iron, and steel, and have a moderate effect on softer metals likealuminum and copper.

In the paper industry in the last three decades, GCC produced frommarble, and to a lesser extent limestone and chalk, has earned theacceptance of important segments of global paper production. GCC is nowthe primary filler and coating pigment used in free sheet coated anduncoated papers. Its advantages are also being recognized in the successof its growing use in ground wood HWC, MWC and LWC coated papers. Theuse of CaCO₃-containing post-consumer wastes in the fiber mix for makingground wood SC papers favors natural GCC as the primary filler alongwith kaolin and talc. GCC has proven to be an important technologicaland economic advantage in papermaking in all the world's major producingareas, including Europe, North and South America, Australia, Asia andAfrica. Building on the primary attributes of brightness and rheology,GCC continues to grow as a major pigment in value-added coatingapplications around the world. Printability and improved economics alsoadd to its popularity. Ultra-fine GCC products are being used in gradesfrom LWC to board; at levels of up to 100% in pre-coats; and at levelsof up to 80% in free sheet topcoats. GCC products now represent morethan 55% of the total coating pigment usage in Europe, and similarpotential is apparent in North America. Depending upon the application,in the paper industry the median particle size of CaCO₃ used ranges from0.4 to 3.2 microns, preferably from 0.4 to 1.4 microns, with theparticle size percent less than 2 microns ranging from as little as 35%to as high as 98%, preferably ranging from 60% to 98%, and most oftenfrom 90% to 98%.

In the paint and coating industries, calcium carbonate has establisheditself as a primary extender for paints. Important properties are itsnon-toxicity, low intrinsic color, weather resistance, low abrasiveness,low electrolyte content and pH stabilizing effect. The binder demand islow due to its particle shape and packing fraction. Fineness andparticle size distribution determine the opacity. Hydrophobic calcitesimprove the anti-corrosion and rheological properties of coatings. Thediameter of the primary particles is close to the size required toachieve maximum scattering of light, permitting the partial replacementof expensive white pigments. Further developments are coating systemswith carefully designed packing which introduces capillaries, shorteningdrying times. This is particularly important for water-based systems. Inthese applications, the particle size of the CaCO₃ ranges from about 0.7to about 24 microns depending upon the degree of opacity and whitenessdesired, and the whiteness ranges from about 85% to about 98%. The roleof ground calcium carbonate in adhesives, caulks and sealants is toreduce cost and improve physical properties. These fine ground powdershave tightly controlled particle distribution to allow for high loadinglevels and reduced resin demand. Special care is given to control largeparticles to provide smooth finishes. The role of ground calciumcarbonate in joint compounds is to serve as a functional mineral of highbrightness with low binder demand to accomplish excellent shrinkagecontrol. Additionally, careful attention is paid to controlling the topsize to prevent problems associated with over size particles (grit).

The addition of fine ground calcium carbonate in PVC formulationsprovides great economic benefits by extending the polymer, enhancingmany physical properties and improving the processabilitycharacteristics of the compound. In almost every opaque application,calcium carbonate filled PVC has proven to be a cost effective addition.Improved products can be manufactured and have successfully replacedmore costly ones. Calcium carbonate helps prevent the buildup ofmaterial in complicated tools improving the surface finish of the finalproduct. Flexible PVC compounds can be customized relative to hardness,tensile properties, flexural properties and surface gloss by selectingthe appropriate loading, and particle size of the carbonate. In sheetmolding compound, unsaturated polyester filled with 40% fine groundcalcium carbonate is widely used in the appliance and automotiveindustries. The role of calcium carbonate is to control viscosity,control the coefficient of thermal expansion, add strength to thepolymer, and lower the cost of the finished product. The addition ofcalcium carbonate with closely controlled properties allows the producerto make a product that successfully rivals steel and aluminum.Consistency in the particle size and particle size distribution ofcalcium carbonate is essential to give controllable viscosity. Fineparticle size is needed to get class ‘A’ surfaces on molded parts.

Calcium carbonate has demonstrated performance in a variety ofpolyolefin markets including diaper film, furniture, constructionmaterials, automotive products, trash and garbage bags, pipe, largegarbage cans, food containers, synthetic paper and bottles to name afew. Performance benefits such as significantly increased output (linearrate or cycles) and improvement of many physical properties areachievable. Increased output is obtained since calcium carbonate hasthermal conductivity over five (5) times greater than PE or PP. Use of15% and 30% by weight of fine calcium carbonate (1.5 microns) is optimumdepending on the product being manufactured and the resin beingemployed. The role of ground calcium carbonate in vinyl flooring is toserve as a mineral with high whiteness and low PVC resin demand.

Zeolites are materials, sometimes referred to as molecular sieves, withdiscreet channels and cages that allow the diffusion of molecules intoand out of their crystalline structures. The utility of these materialslies in their microstructures that allow access to large internalsurface areas and that increase adsorptive and ion exchange capacity.

Solids, liquids or gases (preferably liquids and gases) are trapped byzeolites via strong physical and/or chemical forces, such as ionicforces, covalent forces and electrostatic attractions. These trappedsolids, liquids, or gases can be released by the application of heat,change in pressure or by displacement with another material, leaving thecrystal structure of the molecular sieve in the same physio-chemicalstate as when the trapped solid, liquid or gas entered. The trapping andrelease are generally substantially completely reversible with therespective isotherm curves coinciding completely, or nearly so. Isothermcurves can be used to determine the manner in which to regulate thetrapping and release of the adsorbed material(s).

Zeolites possess a very high surface area; for example, the externalsurface area of zeolites only comprises approximately one percent (1%)of the total surface area. Zeolites have been proposed for use inplastic and wood-plastic composites, and zeolites have also beenproposed as carriers for foaming agents in the production of plastic(thermoset and thermoplastic) foams and in wood-plastic composite foams.The entire surface area of the zeolite is capable of and available fortrapping the foaming agent(s). Therefore, the external surface area ofthe zeolites is available for adsorbed material(s) of all sizes, whereasthe internal surface area is available only to molecules small enough toenter the pores. However, because the external surface comprisesapproximately one percent (1%) of the total surface area, materials toolarge to be trapped within the pores will usually only be held by theexternal surface to the extent of 0.2 to 1 weight percent.

The zeolite framework is made up of SiO₂ tetrahedra linked by sharedoxygen atoms. Substitution of aluminum for silicon creates a chargeimbalance that requires a non-framework cation to balance the charge.These cations, which are contained inside the channels and cages ofthese materials, may be replaced by other cations giving rise to ionexchange properties. The zeolites also contain water of hydration aspart of their structure. The water of hydration in these materials maytypically be reversibly removed leaving the host structure intact,although some framework distortion may occur. In addition, zeolitematerials are typically alkaline. Suspensions of low SiO₂:Al₂O₃ ratiomaterials in water often give rise to a pH greater than 9. Thiscombination of alkalinity and the pore structure of these compounds isbelieved to be largely responsible for the ability of these zeolites tostabilize halogenated polymers by neutralizing acids released duringprocessing and creating inert salts and/or scavenging excess cationicmetals.

Zeolites are frequently categorized by their crystalline unit cellstructure (See W. M. Meier, D. H. Olson, and Ch. Baerlocher, Atlas ofZeolite Structure Types, Elsevier Press (1996) 4th ed.). Those suitablefor use in the present disclosure include compounds characterized aszeolite A, zeolite P, zeolite X, and zeolite Y. In the presentdisclosure, any suitable zeolite can be used as is for those applicationwhere foaming agents will not be employed, or the zeolites may be usedto trap the desired foaming agent for foaming applications. For foamingapplications, the appropriate zeolite is dependent on the size,electronegativity and polarizability of the adsorbed material(s) desiredto be trapped. Appropriate zeolites for the present disclosure include,but are not limited to, Type 3A, 4A, 5A, 13× and combinations thereof(the A represents angstroms, and 13× has a pore size greater than 5A).

A wide variety of zeolites are available, each with its own specific anduniform pore size. This variety allows for the zeolite to be chosen onthe basis of the material to be trapped. Generalized pore size andadsorption characteristics of type 3A, 4A, 5A and 13× molecular sievesare as follows: Type 3A may be used to trap molecules with an effectivediameter of less than 3 angstroms, including, for example, water andammonia, and excludes molecules with a diameter of more than 3angstroms, such as ethane. Type 4A may be used to trap molecules with aneffective diameter of less than 4 angstroms, including, for example,ethanol, hydrogen sulfide, carbon dioxide, sulfur dioxide, ethylene,ethane, and propene, and excludes molecules with an effective diametergreater than 4 angstroms, such as propene. Type 5A may be used to trapmolecules having an effective diameter of less than 5 angstroms,including, for example, n-butanol, n-butane, saturated hydrocarbons frommethane to molecules containing twenty-two carbons, R-12, and excludesmolecules having an effective diameter of greater than 5 angstroms,including iso-compounds and four carbon ring compounds. 13× may be usedto trap molecules having an effective diameter less than 10 angstroms,and excludes molecules having an effective diameter greater than 10angstroms. Each type molecular sieve may trap molecules of the lowertype, i.e., Type 5A may adsorb molecules adsorbed by Type 4A, and soforth. However, trapping of the foaming agent(s) may be more efficientusing a zeolite with pore size more closely analogous to the size of themolecule being trapped, especially in effective retention of the trappedadsorbed material(s) prior to and during processing.

The zeolites useful in the present disclosure may be generallydesignated by the chemical formula M₂/nO.Al₂O₃.ySiO2.wH₂O in which M isa charge balancing, exchangeable cation, n is the valence of M and is 1or 2, y is the number of moles of SiO₂ and is about 1.8 to about 15, andw is the number of moles of water of hydration per molecule of thezeolite. Suitable charge balancing cations represented by M in theformula include such cations as sodium, potassium, zinc, magnesium,calcium, ammonium, tetra-alkyl and/or -aryl ammonium, lithium, Ag, Cd,Ba, Cu, Co, Sr, Ni, Fe, and mixtures thereof. The preferred cations arealkali metal and/or alkaline earth metal cations, with the proviso that,when M is a mixture of alkali or alkaline earth metals comprising sodiumand potassium and/or calcium, the preferred potassium and/or calciumcontent is less than about 35% by weight of the total alkali or alkalineearth metal content.

The size and position of the exchangeable cation (Na, Ca, etc.) mayaffect the pore size in any particular type of zeolite. For example, thereplacement of sodium ions in Type 4A with calcium ions produces Type5A, with a free aperture size of 4.2 angstroms. Not wishing to be boundby any theory, the cations are also probably responsible for the verystrong and selective electronic forces which are unique to theseadsorbents. In the case of zeolites, selectivity is influenced by theelectronic effects of the cations in the cavity as well as the size ofthe apertures in the alumino-silica framework. Therefore, zeolites canbe tailored to “trap” specific molecules by varying the size of thepores and the attractive forces.

As mentioned, zeolites will not only separate molecules based on sizeand configuration, but they will also trap preferentially based onpolarity or degree of chemical unsaturation. Therefore, molecules areheld more tightly in the crystal structure if they are less volatile,more polar, or less chemically saturated. Some of the strongest trappingforces are due to cations acting as sites of strong, localized, positivecharge that electrostatically attract the negative end of polarmolecules. Polar molecules are molecules containing heteroatoms such asO, S, CI, F, or N and are usually asymmetrical. Dipole moments can alsobe induced by cations present in the zeolites, resulting in theattraction of sites of unsaturation over saturated bonds. In view ofthese means of attraction, the ability of zeolites to trap and hold thefoaming agent is based not only on molecular size, but additionally onthe basis of electronic forces. For example, zeolites will trap water inpreference to argon and olefins in preference to saturated hydrocarbons.

While the number of moles of SiO₂ per molecule of aluminosilicate,represented in the formula by “y”, may be in the range of about 1.8 orgreater, it is suitably about 1.85 to about 15, more suitably about 1.85to about 10, preferably in the range of about 2 to about 5, and morepreferably in the range of about 1.8 to about 3.5. The number of molesof water in the zeolite as water of hydration, represented in theformula by “w”, is generally greater than about 0.1, more generally inthe range of about 0.1 to about 10.

It is desirable that the zeolite have a mean particle size in the rangeof about 0.1 to about 10 microns, suitably wherein at least about 90% ofthe particles are less than about 50 microns, advantageously less thanabout 25 microns, and more advantageously less than about 10 microns. Itis also desirable that the zeolite have a mean micropore diameter in therange of about 2.8 to about 8A, and/or an external surface area in therange of about 3 to about 300 square meters/g.

In the present disclosure, the most preferred zeolites are the ADVERA401 PS, ADVERA 401P and ADVERA 401F sodium aluminosilicate hydrated typeNa-A zeolite powders, all available from PQ Corporation. Each of theADVERA zeolites has: an average nominal chemical composition of 17%Na₂O, 28% Al₂O₃, 33% SiO₂, and 22% H2O; a nominal pore size diameter of4 A; and a moisture loss at 800 degrees C. of 18%-22% by weight. Thesezeolites vary somewhat in average particle size and particle sizedistribution.

Halloysite, a naturally occurring aluminosilicate nanotube, is atwo-layered aluminosilicate, with a predominantly hollow tubularstructure in the submicron range and chemically similar to kaolin.Halloysite typically forms by hydrothermal alteration ofalumino-silicate minerals. It can occur intermixed with dickite,kaolinite, montmorillonite and other clay minerals. X-ray diffractionstudies are required for positive identification. The formation ofhalloysite is due to hydrothermal alteration, and it is often found nearcarbonate rocks. For example, halloysite samples found in Colorado aresuspected to be the weathering product of rhyolite by downward movingwaters. In general, the formation of clay minerals is highly favored intropical and sub-tropical climates due to the immense amounts of waterflow. Halloysite has also been found overlaying basaltic rock, showingno gradual changes from rock to mineral formation. Halloysite occursprimarily in recently-exposed volcanic-derived soils, but it also formsfrom primary minerals in tropical soils or pre-glacially weatheredmaterials. Igneous rocks, especially glassy basaltic rocks are moresusceptible to weathering and alteration forming halloysite.

Halloysite is often found in close association with goethite andlimonite and often interspersed with alunite. Feldspars are also subjectto decomposition by water saturated with carbon dioxide. When feldsparoccurs near the surface of lava flows, the CO₂ concentration is high,and reaction rates are rapid. With increasing depth, the leachingsolutions become saturated with silica, aluminium, sodium, and calcium.Once the solutions are depleted of CO₂ they precipitate as secondaryminerals. The decomposition is dependent on the flow of water. In thecase that halloysite is formed from plagioclase it will not pass throughintermediate stages.

Halloysite is a 1:1 aluminosilicate clay mineral with the empiricalformula Al₂Si₂O₅(OH)₄. It also contains water of hydration. Its mainconstituents are aluminium (20.90%), silicon (21.76%), and hydrogen(1.56%). The neighboring alumina and silica layers, and their waters ofhydration, form curves and multilayer tubes due to a packing disorder.Halloysite is an economically viable material that can be mined from thecorresponding deposit as a raw mineral. As for most natural materials,the size of halloysite particles varies within 1-15 microns in lengthand 10-150 nm in inner diameter, depending on the deposits. Thismaterial has an average tube diameter of 50 nm and inner lumen diameterof 15 nm. Typically, a nominal specific surface area of halloysite is 65m2/g; pore volume of ˜1.25 mL/g; refractive index 1.54; and specificgravity 2.53 g/cm3. Chemically, the outer surface of the halloysitenanotubes has properties similar to SiO₂ while the inner cylinder coreis related to Al₂O₃. The charge (zeta potential) behavior of halloysiteparticles can be roughly described by superposition of mostly negative(at pH 6-7) surface potential of SiO₂, with a small contribution fromthe positive Al₂O₃ inner surface. The positive (below pH 8.5) charge ofthe inner lumen promotes loading of halloysite nanotubes with negativemacromolecules, which are at the same time repelled from the negativelycharged outer surfaces.

These unique tubes can be dispersed by normal extrusion processes in avariety of polymer melts to produce nanocomposites with unusual physicalproperties. Their addition reduces the polymer MIF, making for moreeasily controlled mixing and extrusion. Dispersions can be made directlyto the desired working composition or a concentrate may be let down tothat concentration. Injection molded parts or blown films have beenproduced from a variety of different polymers, including nylon,polypropylene, and several varieties of polyethylene. The halloysitenanotubes can also be dispersed into polymer latexes and dispersions inorder to produce coating formulations which in turn produce coatingswith advantaged physical properties. The various polymer concentratesand surface treated methodologies allow easy routes into improvedpolymer performance.

Both hydrophobic and hydrophilic agents can be entrapped in halloysitenanotubes after an appropriate pre-treatment of the halloysite surface.Macromolecular release profiles from the halloysite are well describedby a one-dimensional diffusion model through the nanotube lumen opening.A wide range of active agents, including drugs, nicotinamide adeninedinucleotide (NED), and marine biocides, can be entrapped within theinner lumen, as well as within void spaces of the multilayeredaluminosilicate shells. This entrapment can be followed by retention andrelease of the agents, making the halloysite a nanomaterial well suitedfor macromolecular delivery applications. Other applications employinghalloysite nanotubules may include control of loading and release ofmacromolecules by making stoppers or narrowing the exits from thenanotubule lumen, and development of the tubule nanoreactor concept bycarrying out reactions at the openings of the halloysite nanotubulesbetween loaded molecules and molecules in bulk solution. Possibleapplications of halloysite nanotubes include controlled release ofanti-corrosion agents, sustained release of herbicides, insecticides,fungicides and anti-microbials, sustained release of drugs, foodadditives, and fragrances, templating synthesis of rod-likenanoparticles, uses as catalytic supports and molecular sieves, specificion adsorption, use as plastic fillers for strength reinforcement andscratch protection, use in advanced ceramic materials, especiallybiocompatible implants.

PTFE is a thermoplastic polymer which is a white solid at roomtemperature, with a density of about 2.2 g/cm³. According to publishedliterature, its melting point is 327° C. (621° F.), but its mechanicalproperties degrade above 260° C. (500° F.). PTFE gains its propertiesfrom the aggregate effect of carbon-fluorine bonds, as do allfluorocarbons. The coefficient of friction of plastics is usuallymeasured against polished steel. PTFE's coefficient of friction is 0.05to 0.10, which is the third-lowest of any known solid material. PTFE'shas excellent resistance to van der Waals forces as well. PTFE also hasexcellent dielectric properties. This is especially true at high radiofrequencies, making it suitable for use as an insulator in cables andconnector assemblies and as a material for printed circuit boards usedat microwave frequencies. Combined with its high melting temperature,this makes it the material of choice as a high-performance substitutefor the weaker and lower melting point polyethylene that is commonlyused in low-cost applications.

Because of its chemical inertness, PTFE cannot be cross-linked like anelastomer. Therefore, it has no “memory” and is subject to creep. Thisis advantageous when used as a seal, because the material creeps a smallamount to conform to the mating surface. However, to keep the seal fromcreeping too much, fillers are used, which can also improve wearresistance and reduce friction. Sometimes, metal springs applycontinuous force to PTFE seals to give good contact, while permitting abeneficially low percentage of creep.

Owing to its low friction, PTFE is used for applications where slidingaction of parts is needed: plain bearings, gears, slide plates, etc. Inthese applications, it performs significantly better than nylon andacetal, and is comparable to ultra-high-molecular-weight polyethylene(UHMWPE), although UHMWPE is more resistant to wear than PTFE. For theseapplications, versions of PTFE with mineral oil or molybdenum disulfideembedded as additional lubricants in its matrix are being manufactured.PTFE's extremely high bulk resistivity makes it an ideal material forfabricating long-life electrets, useful devices that are theelectrostatic analogues of magnets. Gore-Tex is a material incorporatinga fluoropolymer membrane with micropores. The roof of the Hubert H.Humphrey Metrodome in Minneapolis is one of the largest applications ofTeflon PTFE coatings, using 20 acres (81,000 m²) of the material in adouble-layered, white dome, made with PTFE-coated fiberglass, whichgives the stadium its distinctive appearance. The Millennium Dome inLondon is also made with a substantial use of PTFE coatings.

Powdered PTFE is used in pyrotechnic compositions as an oxidizertogether with powdered metals such as aluminium and magnesium. Uponignition, these mixtures form carbonaceous soot and the correspondingmetal fluoride, and release large amounts of heat. Hence they are usedas infrared decoy flares and igniters for solid-fuel rocket propellants.In optical radiometry, sheets made from PTFE are used as measuring headsin spectroradiometers and broadband radiometers (e.g., illuminancemeters and UV radiometers) due to PTFE's capability to diffuse atransmitting light nearly perfectly. Moreover, optical properties ofPTFE stay constant over a wide range of wavelengths, from UV up to nearinfrared. In this region, the relation of its regular transmittance todiffuse transmittance is negligibly small, so light transmitted througha diffuser (PTFE sheet) radiates like Lambert's cosine law. Thus, PTFEenables co-sinusoidal angular response for a detector measuring thepower of optical radiation at a surface, e.g., in solar irradiancemeasurements. PTFE is also used to coat certain types of hardened,armor-piercing bullets, so as to prevent the increased wear on thefirearm's rifling that would result from the harder projectile, howeverit is not the PTFE itself that gives the bullet its armor-piercingproperty. High corrosion resistance favors the use of PTFE in laboratoryenvironments as containers, as magnetic stirrer coatings, and as tubingfor highly corrosive chemicals such as hydrofluoric acid, which willdissolve glass containers. PTFE is also widely used as a thread sealtape in plumbing applications, largely replacing paste thread dope. PTFEmembrane filters are among the most efficient used in industrial airfiltration applications. Filter coated with a PTFE membrane are oftenused within a dust collection system to collect particulate matter fromair streams in applications involving high temperatures and highparticulate loads such as coal-fired power plants, cement production,and steel foundries. PTFE grafts can be used to bypass stenotic arteriesin peripheral vascular disease, if a suitable autologous vein graft isnot available. PTFE can be used to prevent insects climbing up surfacespainted with the material. PTFE is so slippery that insects cannot get agrip and tend to fall off. For example, PTFE is used to prevent antsclimbing out of formicaria. A particular use of PTFE particles is inanti-drip agents useful as an additive in flame-retardent plactics. Forexample, DAIKIN-POLYFLON MPA is a white powder made from PTFE resinwhich has been developed as an additive to prevent dripping whenplastics burn.

Preferred Adhesion/Adherence Promoting Material

The preferred adhesion/adherence promoting component is thermoplasticneutralized ethylene-acrylic acid copolymers. The thermoplasticneutralized ethylene-acrylic acid copolymers are made from anethylene-acrylic acid copolymer which has been neutralized by an aminecontaining compound such as ammonia, monoethylethanol amine ordiethylethanol amine. The acid in the copolymer can be acrylic acid,methacrylic acid, ethacrylic acid, maleic acid, and itaconic acid. Thesecompounds have demonstrated the ability to carry a high pigment load andcan be dispersed with a wide variety of materials. The term“thermoplastic” refers to a material which is capable of beingrepeatedly softened when it is heated and hardened when it is cooled.The term “neutralized” refers to replacing H+ with other cations. Theacid units in the present invention include acrylic acid, methacrylicacid, ethacrylic acid, maleic acid, and itaconic acid.

The term “ethylene-acrylic acid copolymers” refers to a polymercontaining ethylene units and acid units. The acid units in the presentdisclosure include acrylic acid, methacrylic acid, ethacrylic acid,maleic acid, and itaconic acid. The thermoplastic neutralizedethylene-acrylic acid copolymer comprises from about 1% to about 99%ethylene-acrylic acid copolymer with a molecular weight of about 1,000to about 300,000 wherein the acid is selected from the group consistingacrylic acid, methacrylic acid, ethacrylic acid, maleic acid, anditaconic acid; and from about 1% to about 9% of a fugitive or asemifugitive cation selected from a group consisting of: ammonia,monoethylethanol amine, and diethylethanol amine. Most preferred as theneutralized ethylene-acrylic acid copolymer is the family of SEKURproducts available from Reedy International Corporation, 25 FrontStreet, Keyport N.J. Most preferred are SEKUR-CN25, SEKUR OP-950 andSEKUR-CN35.

Preferred Additive

The preferred additive for the present disclosure is one or morecolorant. Any of the colorant additives known to those skilled in theart may be used, including those mentioned in the aforementioned patentdocuments. The colorants may be powder or liquid. Pigments which can beused include, but are not limited to, carbon black (LUCONYL Black), azopigment (LUCONYL yellow), copper phthalocyanine beta (LUCONYL Blue),iron oxide (LUCONYL red), copper phthalocyanine chlorinated (LUCONYLGreen), and titanium dioxide (LUCONYL White). These pigments areavailable under the LUCONYL trademark from BASF AG, Lugwigshafen,Germany. Also as pigments may be used carbon black (Monarch),Quinacridone red (Sun Chemical) and Umber Iron Oxide (Cathay Pigments).As dyes may be used basic blue dye, Red 55 mixed metal dye (Mitsui) andFD&C Yellow No. 5. Dyes are preferred above pigments in the presentdisclosure.

Dryer Apparatus

The preferred dryer apparatus of the present disclosure comprises apulse combustion or spray dryer. Pulse combustion dryers and spraydryers are used to dry a variety of materials. The materials may beintroduced into a drying gas stream through one or more introductiondevices, which include nozzles tubes, orifices, and other suchstructures adapted to introduce the materials into the drying gasstream. However, the materials to be dried can be highly viscous.Frequently, the materials to be dried take the form of slurry, paste, orother non-readily flowable form that tends to clog the introductiondevice. During the drying process, these materials may form clumps,aggregations, agglomerations, and other non-uniformities in theintroduction device. Some variations of pulse combustion dryers may failto adequately break up these clumps as the material is introduced intothe drying gas stream. Although typical pulse combustion and spraydryers may be used for some applications with respect to the slurriesaccording to the present disclosure, they may fail to produce agenerally uniform dried material in terms of moisture content and/ormaterial size which in many applications of pulse combustion dryers isthe desired result.

Therefore, the most preferred dryer apparatus for use with the presentdisclosure is one according to the disclosure of U.S. Pat. No.7,988,074. In that disclosure, a material dispersion apparatus isprovided which includes a nozzle. The nozzle may define a mixing chamberhaving a mixing chamber inlet and a mixing chamber outlet, and themixing chamber may be adapted to receive material through the mixingchamber inlet. The nozzle defines a plenum radially disposed withrespect to the mixing chamber, and the plenum has a plenum inlet throughwhich the plenum receives gas. The nozzle defines one or more gas portsin fluid communication with the plenum and in fluid communication withthe mixing chamber to flow gas from the plenum into the mixing chamber.The nozzle defines a gap having a gap outlet, and the gap is in fluidcommunication with the plenum to flow gas from the plenum through thegap and out the gap outlet to cool at least a portion of the nozzle invarious aspects. The material dispersion apparatus includes a venturiand the venturi is disposed downstream of the nozzle such that a plumeof material ejected from the mixing chamber outlet passes through aventuri throat of the venturi. In use, a drying gas stream is flowedpast the nozzle, introducing material into a mixing chamber of thenozzle; swirling the material within the mixing chamber by injecting gasinto the mixing chamber; forming a plume in the drying gas stream byejecting the material from the mixing chamber into the drying gasstream; shaping the plume by positioning a body within the mixingchamber, and passing the plume through a venturi throat of a venturi.

It has been found that using a pulse dryer apparatus such as disclosedin U.S. Pat. No. 7,988,074 minimizes clumping and agglomeration of thecolorized coated fillers of the present disclosure, and that the yieldand quality of the resulting additive-containing coated fillers, isimproved over conventional pulse dryer apparatuses.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The examples which follow are by no means intended to limit thedisclosure, but are intended for exemplary purposes only and are notintended to limit the disclosure in any manner whatsoever, but areintended to merely describe those embodiments presently preferred.Percentages in the examples that follow are in weight %. In some of theexamples, no water needed to be added to for the slurry/mixture becausethere was sufficient SEKUR to form the slurry/mixture.

EXAMPLES

Example A *CaCO₃ 78.00% Water 22.00% Example B *CaCO₃ 60.00% Sekur CN-3540.00% Example C *CaCO₃ 45.00% Sekur OP-950 43.00% Water 12.00% ExampleD *CaCO₃ 38.00% Sekur CN-35 26.00% Water 36.00% Example E *CaCO₃ 45.00%Sekur CN-25 35.00% Sodium Bicarb. 20.00% Example F *CaCO₃ 45.00% SodiumBicarb. 20.00% Sekur OP-95 35.00%

Example 1 *CaCO₃ 41.32% Sekur CN-35 20.66% Sekur OP-950 20.66% Basicblue dye 0.83% Water 16.53% Example 2 *CaCO₃ 30.10% Sekur OP-950 34.25%Sekur CN-35 34.25% Basic blue dye 1.40% Example 3 *CaCO₃ 25.20% SekurCN-35 29.90% Sekur OP-950 29.90% Basic blue dye 1.20% Water 13.80%Example 4 *CaCO₃ 26.00% Sekur OP-950 73.00% Basic blue dye 1.00% Example5 *CaCO₃ 49.50% Basic blue dye 0.50% REZ 50.00% Example 6 *CaCO₃ 78.00%Red dye 55 1.00% Water 21.00%*Calcium carbonate available from OMYA Corp. under the trademarkOmyacarb UFT-FL.

The above compositions were slurried thoroughly and passed through apulse dryer apparatus available from J. Jireh, referred to in paragraphsabove. Example A was performed to show that the drying process using thepulse dryer apparatus available from J. Jireh could provide a fine,non-agglomerated CaCO₃ particle powder from the slurry of CaCO₃ and H₂O.The powder that was produced was a fine non-agglomerated CaCO₃ powder.Examples B-F were performed and showed that a plurality of substantiallyuniformly coated fine, non-agglomerated particles was obtained. Theresulting particles of Examples B-F were substantially uniformly coatedwith the Sekur neutralized ethylene-acrylic acid copolymer. Examples 1-5produced a plurality of fine, non-agglomerated colored free-flowingparticles with the dye adhering well to the filler via the Sekurneutralized ethylene-acrylic acid copolymer. The dye adhered to theSekur neutralized ethylene-acrylic acid copolymer and thus the fillersubstantially uniformly. The filler particles thus were substantiallyuniformly coated with the dye.

The above colored filler particles can be added to polymeric materialsand extruded into foam or non-foam articles of manufacture. Typicalprocessing apparatuses and processes may be used to produce such foam ornon-foam materials and the processing need not have any particularlyspecial or detailed parameters. The above procedures and materials foradhesion promotion and coloring may likewise be used with any of thefillers described herein, as well as additional filler materials aswould be appreciated by those of skill in the art.

In the above detailed description, the specific embodiments of thisdisclosure have been described in connection with its preferredembodiments. However, to the extent that the above description isspecific to a particular embodiment or a particular use of thisdisclosure, this is intended to be illustrative only and merely providesa concise description of the exemplary embodiments. Accordingly, thedisclosure is not limited to the specific embodiments described above,but rather, the disclosure includes all alternatives, modifications, andequivalents falling within the true scope of the appended claims.Various modifications and variations of this disclosure will be obviousto a worker skilled in the art and it is to be understood that suchmodifications and variations are to be included within the purview ofthis application and the spirit and scope of the claims.

All of the above patents and publications and all of the disclosurecontained therein are incorporated herein in their entirety as if fullyset forth herein.

What is claimed is:
 1. A process for producing a filler having anadhesion-promoting material coating comprising: (a) preparing a mixtureor slurry comprised of filler; (b) adding to the slurry obtained in step(a) a material which promotes adhesion of desired additive(s) to thefiller to form an adhesion-promoting material-coated filler mixture orslurry, wherein the adhesion-promoting material comprises neutralizedethylene-acrylic acid (EAA) copolymer; and (c) passing the mixture orslurry from step (b) through a pulse dryer to obtain a dried fillercoated with the adhesion-promoting material.
 2. The process according toclaim 1, wherein the filler is free-flowing, substantially free ofagglomerates and substantially uniformly coated with theadhesion-promoting material.
 3. The process according to claim 1,wherein the filler is selected from the group consisting of calciumcarbonate, halloysites, PTFE particles, zeolite, and combinations of anyof the foregoing.
 4. The process according to claim 1, wherein thefiller is calcium carbonate.
 5. A process for producing a filler havingan adhesion-promoting material coating comprising: (a) preparing amixture or slurry comprised of filler selected from the group consistingof calcium carbonate, halloysites, PTFE particles, zeolite, andcombinations of any of the foregoing; (b) adding to the slurry ormixture obtained in step (a) a material which promotes adhesion ofdesired additive(s) to the filler to form an adhesion-promotingmaterial-coated filler mixture or slurry, wherein the adhesion-promotingmaterial comprises neutralized ethylene-acrylic acid (EAA) copolymer;and (c) drying the additive-containing filler from (c) by passing themixture or slurry through a pulse dryer to obtain filler coated with theadhesion-promoting material, wherein the pulse dryer comprises a nozzlethat includes a mixing chamber having a mixing chamber inlet and amixing chamber outlet, and wherein the mixing chamber is designed andconfigured to receive the slurried suspension or mixture ofadditive-containing filler through the mixing chamber inlet.
 6. Theprocess according to claim 5, wherein the filler is free-flowing,substantially free of agglomerates and substantially uniformly coatedwith the adhesion-promoting material.
 7. The process according to claim5, wherein the filler is calcium carbonate.
 8. The process according toclaim 1, wherein the additive-containing filler is dried using stepscomprising: (i) flowing a drying gas stream past a nozzle, (ii)introducing the additive-containing filler into a mixing chamber of thenozzle; (iii) swirling the additive-containing filler within the mixingchamber by injecting gas into the mixing chamber; (iv) forming a plumein the drying gas stream by ejecting the additive-containing filler fromthe mixing chamber into the drying gas stream; (v) shaping the plume bypositioning a body within the mixing chamber; and (vi) passing the plumethrough a venturi throat of a venturi, wherein the venturi is disposeddownstream of the nozzle.
 9. A process for producing a filler having anadhesion-promoting material coating, the process comprising: (a)preparing a mixture or slurry comprised of filler and adhesion-promotingmaterial, wherein the adhesion-promoting material comprises neutralizedethylene-acrylic acid (EAA) copolymers; and (b) passing the mixture orslurry through a pulse dryer to obtain a dried filler coated with theadhesion-promoting material.
 10. A filler made according to the processof claim
 1. 11. A filler made according to the process of claim
 5. 12. Afiller made according to a process comprising: (a) preparing a mixtureor slurry comprised of filler selected from the group consisting ofcalcium carbonate, halloysites, PTFE particles, zeolite, andcombinations of any of the foregoing; (b) adding to the slurry ormixture obtained in step (a) a material which promotes adhesion ofdesired additive(s) to the filler to form material-coated filler mixtureor slurry, wherein the adhesion-promoting material comprises neutralizedethylene-acrylic acid (EAA) copolymer; (c) adding to the material-coatedfiller mixture or slurry obtained in step (b) an additive which impartsto the filler desired additive properties to form a slurried suspensionor mixture of additive-containing filler, wherein the additive is a dyeselected from the group consisting of basic blue dye, red 55 mixed metaldye, FD&C yellow dye no. 5, a pigment selected from the group consistingof carbon black, azo pigment, copper phthalocyanine beta, iron oxide,copper phthalocyanine chlorinated, and titanium dioxide, quinacridonered, umber iron oxide and combinations of any of the foregoing; and (d)drying the additive-containing filler from (c) by passing the mixture orslurry through a pulse dryer to obtain filler coated with the adhesionpromoting material material and additive.